Method and means for sorting objects according to length



Sept. 30, 1969 E. M. ERVIN 3,469,690

METHOD AND MEANS FOR SORTING OBJECTS ACCORDING TO LENGTH Filed July 28,1967 1 T N NM 0 s 8: 4; Ma a x O I INVENTOR '1 q EVANDER M. ERVIN V BY ma m T 3, N "bum! 145mg:

ATTORNEYS United States Patent O 3,469,690 METHOD AND MEANS FOR SORTINGOBJECTS ACCORDING TO LENGTH Evander M. Ervin, Florence, S.C. Terleco,Inc., 3000 Southwest Blvd., Charlotte, NC, 28208) Continuation-impart ofapplication Ser. No. 640,733, May 23, 1967. This application July 28,1967, Ser. No. 667,020

Int. Cl. B07c 5/04, 1/10; B07b 13/04 U.S. Cl. 209-102 4 Claims ABSTRACTOF THE DISCLOSURE CROSS-REFERENCE TO RELATED APPLICATIONS This is acontinuation-in-part of copending application Ser. No. 640,733, filedMay 23, 1967, and concurrently abandoned in favor of the presentapplication.

BACKGROUND OF THE INVENTION This invention relates generally to thesorting of elongate objects according to length, and more particularlyto such sorting from an indiscriminately mixed supply of objectsdiffering discriminately in length through a substantial range andvariety of selected length possibilities.

Elongate objects of the sort referred to are exemplified by billets ofvarying shorter lengths recovered from imperfect cut stock resultingfrom the operation of tubular sawing means of the type disclosed in U.S.Patent No. 3,163,190 for cutting cylindrical wooden billets from roughlog sections. Such billets are well suited as blanks for many turnedelements employed in furniture construction and the like. A normalconsequence of cutting such billets from rough log sections, however, isa certain percentage of cut stock having imperfect lengthwise portionsfor one reason or another. And because tubular sawing means of the typeindicated renders operation at high production rates possible, a normalpercentage of imperfect cut stock commonly accumulates in sufiicientquantity to warrant reclaiming.

The reclaiming is suitably done at a cropping saw equipped withselective gauging means allowing a maximum usable clear length of theimperfect cut stock to be measured off short of the defective portionbefore removal by the cropping saw. Because the imperfect portions willvary in extent and location, the salvaged clear lengths will likewisevary and produce a reclaim output at the cropping saw that isindiscriminately mixed as to length. By Way of specific example, whenthe tubular sawing is done from log sections that are 46" in length, ithas been found practical to arrange the selective gauging means foralternative cropping of the imperfect cut stock at any of 4", 6", 8",10", 12", 16", 20" or 24" measurements from either end. Thecomplementary clear lengths resulting from the cropping saw operationcomprise an output of mixed character that must then be sorted as tolength for useful reclaiming.

3,469,690 Patented Sept. 30, 1969 The prior art includes proposals forsorting by selective actuation of diverting mechanism in response to asensing of length, as in U.S. Patent No. 3,080,052; as well asarrangements for delivering a dependable supply of elements normallyhaving a given length by discarding imperfect elements from the supplyin the course of delivery, as in U.S. Patents No. 2,501,403 and No.3,106,291.

The method and apparatus of the present invention, on the other hand,effects sorting through direct length dis crimination in a particularlysimple manner providing consistent results at good handling rates.

SUMMARY OF THE INVENTION Generally characterized, sorting isaccomplished according to the present invention by transporting theelongate objects to be sorted in lengthwise succession whileinterrupting the transporting cause at successive intervals sizedprogressively for selectively releasing the objects in spacedprogression according to increasing length. Selective release of theobjects is effected by transiently holding the objects against releaseat the beginning of every interval interrupting the transporting causeas well as at the end of every such interval until reaching the one thatis sized to corresponding length.

BRIEF DESCRIPTION OF THE DRAWING The single figure of the drawingdiagrammatically illustrates an arrangement of sorting means accordingto the present invention and indicates the manner of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawing shows elongateobjects A, B, C and D of varying length in the course of being sorted asto length.

The sorting is done by means of a plurality of serially spaced conveyorsections 10, 12 14 and 16 arranged for transporting the objects A-D tobe sorted in lengthwise succession. The first conveyor section 10 servesin the extent not shown to receive or pick up the objects A-Dindiscriminately from a mixed supply thereof and start them in thelengthwise succession through the sorting course in which the remainingconveyor sections 12- 16 are successively aligned for receiving anobject A-D from a preceding conveyor section 10-14 across the spacingtherebetween whenever the object length will bridge the spacing, whilethese intervening spacings at 18, 20 and 22 are sized in progressivecorrespondence with increasing object length so that the shortest lengthwill not bridge the first spacing 18 and so on.

The conveyor sections 10-16 each include an active transport reachformed by generally horizontal runs 24, 26, 28 and 30 of moving beltstrained over supporting rollers 32 and 34 defining the extent of eachreach, and are additionally provided with holding rollers 36 and 38paired with each supporting roller 32 and 34 at each conveyor spacing18-22 and yieldably biased in opposed relation thereat, either directlyabove or somewhat offset from the related supporting rollers, fortransiently riding and effecting transfer across each such spacing ofall objects A-D that are long enough to bridge the spacing. All conveyorsections 12-16 but the first are also preferably provided with anauxiliary training roller 40 spaced below and sufficiently in advance ofthe supporting roller 32 defining the respective transport reach 26, 28or 30 to dispose a leading upwardly inclined reach 42, 44 or 46 of themoving conveyor belt for righting action at a sagging end of any objectA-D long enough to bridge the spacing 18, 20 or 22 thereat.

The manner in which the sorting takes place is indicated by the drawingillustration in which an object A 3 i of the shortest length included inthe mixed supply to be sorted is shown being released through the firstconveyor spacing 18, while an object B of the next longer length appearsafter having passed across the spacing 18 to the second conveyor section12; a next longer object C is at the point of bridging the secondconveyor spacing 20 under the holding influence of the riding rollers 36and 38 thereat; and the longest object D is seen crossing the lastconveyor spacing 22 and about to have its forward sagging end righted bythe leading inclined reach 46 of the last conveyor section 16.

The lengthwise succession of the objects AD through the conveyor courseis readily maintained by any suitable arrangement of channeling guides(not shown) and any suitable sort of receptacles, as at 48, 50 and 52,may be arranged below the conveyor spacings 18, 20 and 22 to catch andaccumulate a sorted supply of the respective objects A, B and C releasedthereat. The longest object D will simply be delivered by the lastconveyor section 16 for similar accumulation. The number of conveyorsections -16 provided in a particular instance must correspond to thenumber of length variation possibilities in the mixed supply to besorted, and it will be apparent that the succession of conveyor sectionsdescribed can be extended to handle as many possibilities as arepresented by a given length variation pattern.

The present invention has been described in detail above for purposes ofillustration only and is not intended to be limited by this descriptionor otherwise except as defined in the appended claims.

I claim:

1. The method of sorting elongate objects according to length from anindiscriminately mixed supply of such objects having varying lengthsthat differ discriminately within a selected length variation pattern,which method comprises causing objects from said supply to betransported horizontally in lengthwise succession, while interruptingthe transporting cause at successive intervals sized progressively forreleasing said objects from said cause in spaced progression accordingto increasing length, and transiently holding said objects againstrelease at the beginning of every such interval as well as at the end ofevery interval except for the one that is sized to corresponding length.

2. Apparatus for sorting elongate objects according to length from anindiscriminately mixed supply of such objects having varying lengthsthat dilfer discriminately Within a selected length variation pattern,said apparatus comprising a plurality of conveyor means arranged inserially spaced relation for transporting objects from said supply inlengthwise succession, the number of conveyor means corresponding to thenumber of possibilities in said length variation pattern, and thespacing between the conveyor means of said plurality being sized inprogressive correspondence with increasing length possibilities of saidobjects, said spaced conveyor means each having an active transportreach, said active transport reaches being successively aligned forreceiving objects from a preceding reach across the spacingtherebetween,

I and means for transiently holding said objects against release at thebeginning of every such spacing as well as at the end of every spacingexcept for the one that is sized to corresponding length.

3. Apparatus for sorting elongate objects as defined in claim 2 andfurther characterized in that said active transport reaches are formedby generally horizontal runs of moving belts trained over supportingrollers defining the extent of each reach, and in that each of saidholding means is formed by rollers paired with each run definingsupporting rollers at each conveyor spacing and yieldably biased inopposed relation thereat for transiently riding and effecting transferacross each spacing of all objects long enough to bridge the spacing.

4. Apparatus for sorting elongate objects as defined in 7 claim 3 andfurther characterized in that all but the first of said serially spacedconveyor means including an auxiliary training roller spaced below andsufliciently in ad- Vance of each supporting roller defining thebeginning of a transport reach to dispose a leading upwardly inclinedreach of said moving belt for righting action at a sagging forward endof any object long enough to bridge the spacing thereat.

References Cited UNITED STATES PATENTS M. HENSON WOOD, IR., PrimaryExaminer RICHARD A. SCHACHER, Assistant Examiner

